Related Achievements

In Mission 3, carry a UNSC weapon all the way through on Heroic or harder.

Hit the panel on the platform and then hop in the swirling portal to the left. Just ahead you will have your first introduction to the Promethean Crawlers. These creatures have obvious heads, so aim for those. They hunt in packs, but generally attack one at a time. Hide behind a corner and pop each one as it appears.

They drop Suppressors and Boltshots. You probably don't want to replace your scoped Magnum at this time, but feel free to experiment with the others. You can read all about these guns on the Weapons pages. Note that you can charge the Boltshot for an ammo-draining mega (close-range) attack.

In Mission 3, carry a UNSC weapon all the way through on Heroic or harder.

You definitely don't want to drop your Magnum here if you want this extremely tough Achievement. You'll have to keep it for the duration of the mission -- without even dropping it once! That means you'll have to use the Beam Rifle quite often and snipe from afar. This is MUCH easier on Heroic than Legendary. You have to get pretty creative with single weapons -- for instance, you can use Needlers on Watchers to easily explode them.

Ahead you'll encounter two more new enemies. Wait to take them on behind the cover of the cliff wall; eliminating the Crawlers first.

The Knight here is protected by a Watcher, which will both shield it AND revive it from death. It's always best to kill the Watcher before the Knight -- although not necessary.

Use your Magnum to take out the Watcher with the zoomed scope, or you might be able to score a Lightrifle, another new Promethean weapon with an awesome zoomed scope effect. Knights have shields that are blue and must be reduced fully before you can make the final kill shot(s). It's crucial to watch the behavior of Knights, since they will be knocked back and clearly lose their cool blue glow when you knock out their shields.

Don't let them hide -- switch guns if you are low on ammo and pursue them until they crackle out of existence in an orange mini-nova.

You'll need to use these grenades in the next area. There are a handful of Knights here and dozens of Crawlers. Use the caves on the left and right side of the area to take them out. The Lightrifle is extremely helpful here in eliminating the Watchers.

Search the wreckage of the Crawlers for Lightrifle ammo.

Ahead is a Promethean structure with ammo and weapons on either end. Stock up and shoot downwards from this elevated position at the enemies around the Terminal below. That's right -- a Terminal is just ahead!

Mission 3 Terminal

At one point soon after the first few waves of enemies in the level, you experience distortion from your helmet visor. Cortana contacts you about what is causing the distortion. After this exchange, a rocky ramp leads upwards into a Forerunner spire. At the very base of this spire is a hard-to-miss Terminal.

Domain Video Unlocked on Waypoint (You must download and install Halo Waypoint on your Xbox to watch this video outside of the game).

An armory in the hallway above the terminal holds Scattershots. These are sort of a "Promethean Shotgun."

The next area is swarming with enemies and low on ammo and weapons. Your goal here is to destroy three glowing orbs in small buildings around the central structure: the Pylon. Ammo and weapons are well-hidden in the orb rooms themselves.

On harder difficulties it may make more sense to rush this area to conserve ammo: Slip into each building and melee the offending orb, avoiding large packs of enemies using radar and the copious amounts of cover spots.

When you near an orb it will be marked on your HUD. Climb the central tower using the ramps around the rear of the pylon structure. A series of these ramps will get you to the top and to the button you need to activate.

Since taking out all of the Knights is extremely tedious, and nearly impossible, if you can knock out all three orbs it is possible to rush the tower. You can use the Hardlight Shield to protect you if you make it into the tower ramp. Try to at least eliminate the Crawlers before attempting to run into the tower.

In the beam control room you can stock up on Promethean weapons to either side of the entrance. Hit the button.

Back in the central region of the sphere, enter the portal on the right.

You can drop down a hole in the floor ahead on the path here. The Covenant and Prometheans will be going at it in a large pit below.

Use this to your advantage to sneak around the area, melee attacking the biggest threats: Elites. A melee attack from behind while they are distracted will result in a cool assassination animation.

After you clear the area of Covenant, back away and use long-distance weapons to destroy the Watchers and then the Knights.

Legendary Tip: On Legendary, the path leading up from this area is has a few Watchers, a Beam Sentry and some Knights. Use Needlers on the Watchers and on the Beam Sentry. Ditch those and grab a Plasma Pistol to reduce the Knights' shields and then follow up with another weapon -- your Magnum, for instance.

Enter the tunnel past the battlezone and travel up the ramps leading to a new area. At the top you'll find a Knight a few watchers and a powerful Beam Sentry floating in the distance. This enemy is extremely annoying, since it can take a ton of damage -- and can deal it out, too. Luckily it doesn't move.

You may be tempted to pick up a Hardlight Shield here, but the Autosentry you have is probably a better option on tougher difficulties. Throw this out when you are in cover to destroy those pesky Watchers and the Beam Sentry as well.

Ghosts await you in the next area after you destroy the Knight. Using your Ghost, stay far away from the Covenant and take potshots at them. Remember to search the ground where they fall for ammo -- although your Ghost packs an infinite supply. Keep it as long as possible!

Boost through the Jackals guarding the door and head up the ramp. There's an undamaged Ghost and plenty of ammo in a nook on the right in the hallway.

Before leaving the hallway, you need to be prepared for what's on the other side of the door: An Elite making a dash for a Banshee. Run the Elite down and leave the Banshee for now.

Patrol the area and take out the enemy Ghosts, which are tough to eliminate with the Banshee from above due to the chaotic fire at ground level. Once you have them taken care of, return to the Banshee and hop inside.

Legendary Tip: On Legendary you probably want to use the Banshee to take out the Ghost and the Banshees. Fly low to hit the Ghost with a missile, then hang out in the roofed overhang area on the right side until you can make a dash for the nearest orb. Taking on Banshees in Legendary is extremely tough, and sometimes a Plasma Pistol is a safer option. When they swing low, shoot them with a charged shot and try to jack them or stick them with a Plasma Grenade.

Note that there is a replacement Banshee at the base of the cliff to the left of the area entrance. for if/when yours gets too banged up. Take out the other Banshees first with regular fire, then strafe enemies on the ground around the three orbs you need to take out, similar to the previous pylon area.

You can actually hit the orbs with Banshee missiles, but it's tough. You get a checkpoint for each orb you take out.

An easy technique is to land your Banshee alongside the small buildings, hop out, melee attack the orb, then return to the skies.

You can then just pilot your Banshee into the pylon tube entrance, avoiding a messy Elite battle on the pylon tower.

In the beam room, once again stock up on ammo to either side of the doorway. You definitely want a long-range weapon for the next area, like the Lightrifle. You'll also want the Scattershot for close-range Elite kills.

It's a race to the massive sphere between the Chief and the Covenant. Take out the first few Covenant stragglers and then head up the left ramp -- you'll have to hit a button to open it.

Destroy the Elite with the Scattershot and return back down the ramp to snipe. The Autosentry is extremely helpful here.

While the fighting rages around you, your goal is a large doorway up the ramps above either side of the area. Once inside the massive door it will close behind you. You'll have a moment to rest and stock up on ammo.

Step on the large elevator-like pad against the ledge and it will lift you to another large door and a new area to fight in. Work your way left and around the perimeter of the level, stealth-killing Elites. Note that the Needler is especially helpful in taking out the Watchers here, so grab one if you can (but ditch it for a Scattershot up the next ramp).

The final push features several Elites taking on a Beam Sentry and some Knights on a long bridge. Stealth kill the Elites and grab the Fuel Rod Cannon. Use this to eliminate the Beam Sentry.

The three Knights are tough, but a Scattershot can make things easier. The Knight with the Lightrifle is especially irksome, but you can rush him.

The final goal is a pair of pillars up the ramp in front of the massive sphere.